Among Mexican gainers, Vitro's A shares soared 7.1 percent to 7.89, recovering a bit from a recent bout of selling. The shares remain significantly lower than where they stood about a month ago, at 8.61, or from their 11.37 level at the start of the year.

Investors are concerned about Vitro's flat glass division, which should be enjoying a boom amid a flurry of construction in Mexico. First-quarter results, though, disappointed